My AR-10 Wouldn't Run

Published on January 31, 2026
Duration: 1:30

This video details the troubleshooting process for an unreliable CMMG MK3 AR-10 chambered in .308 Win. The host, demonstrating high technical authority, installs and tests the RifleSpeed Gas Control adjustable gas block to address cycling issues exacerbated by a short dwell time and cold weather. The guide focuses on the installation and adjustment of this specific component to improve firearm reliability.

Quick Summary

AR-10 rifles like the CMMG MK3 can face reliability issues due to low dwell time, especially in cold weather (tested at 16.7°F). The RifleSpeed Gas Control, an adjustable gas block with a toolless dial, helps optimize gas flow to ensure consistent cycling and improve overall firearm function.

Chapters

  1. 00:00Intro: CMMG MK3 .308 Win Issues
  2. 00:28AR-10 Reliability Troubleshooting
  3. 00:44RifleSpeed Gas Control Explained
  4. 01:13Cold Weather Testing & Results

Frequently Asked Questions

What causes AR-10 rifles like the CMMG MK3 to be unreliable?

AR-10s, particularly models with short barrels and mid-length gas systems like the CMMG MK3, can suffer from low dwell time. This sensitivity, combined with factors like ammunition type and extreme cold (tested at 16.7°F), can lead to cycling failures.

How does the RifleSpeed Gas Control improve AR-10 reliability?

The RifleSpeed Gas Control is an adjustable gas block that allows precise regulation of gas entering the system. Its toolless dial and drifting plunger mechanism help optimize the rifle's cycling, especially for suppressed use or in adverse environmental conditions.

What are common troubleshooting steps for AR-10 reliability issues?

Common steps include swapping gas blocks, trying different ammunition, adjusting buffer weights, and changing buffer springs. Installing an adjustable gas block like the RifleSpeed is a more advanced solution for fine-tuning gas delivery.

Why is cold weather a challenge for AR-10 function?

Extreme cold, as demonstrated at 16.7°F, can affect lubricant viscosity and metal tolerances, potentially leading to sluggish action and malfunctions such as failures to eject or feed. An adjustable gas block can help compensate for these effects.

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